等徑(jing)四(si)通(tong)(tong)為管件、管道連接件。又叫管件等徑(jing)四(si)通(tong)(tong)或者(zhe)等徑(jing)四(si)通(tong)(tong)管件，等徑(jing)四(si)通(tong)(tong)接頭(tou)，用在主管道要分(fen)支管處。

等徑(jing)(jing)(jing)四(si)(si)(si)通(tong)有等徑(jing)(jing)(jing)和(he)異(yi)徑(jing)(jing)(jing)之分(fen)，等徑(jing)(jing)(jing)等徑(jing)(jing)(jing)四(si)(si)(si)通(tong)的(de)(de)接(jie)管(guan)(guan)(guan)端部均為(wei)相(xiang)同的(de)(de)尺(chi)寸；異(yi)徑(jing)(jing)(jing)的(de)(de)等徑(jing)(jing)(jing)四(si)(si)(si)通(tong)的(de)(de)主(zhu)管(guan)(guan)(guan)接(jie)管(guan)(guan)(guan)尺(chi)寸相(xiang)同，而(er)支管(guan)(guan)(guan)的(de)(de)接(jie)管(guan)(guan)(guan)尺(chi)寸小于主(zhu)管(guan)(guan)(guan)的(de)(de)接(jie)管(guan)(guan)(guan)尺(chi)寸。等徑(jing)(jing)(jing)四(si)(si)(si)通(tong)是用(yong)于管(guan)(guan)(guan)道分(fen)支處的(de)(de)一種管(guan)(guan)(guan)件。對于采用(yong)無縫管(guan)(guan)(guan)制造(zao)等徑(jing)(jing)(jing)四(si)(si)(si)通(tong)來(lai)講，目前通(tong)常所采用(yong)的(de)(de)工藝有液壓(ya)(ya)脹(zhang)形(xing)(xing)和(he)熱(re)壓(ya)(ya)成(cheng)形(xing)(xing)兩(liang)種。

1、液壓脹形

等徑(jing)四(si)(si)通(tong)的(de)液壓(ya)(ya)(ya)(ya)(ya)脹(zhang)形(xing)是通(tong)過(guo)金屬(shu)材(cai)料的(de)軸向補(bu)償脹(zhang)出(chu)(chu)支管(guan)(guan)的(de)一種成(cheng)形(xing)工藝(yi)。其過(guo)程是采用(yong)(yong)液壓(ya)(ya)(ya)(ya)(ya)機，將與等徑(jing)四(si)(si)通(tong)直徑(jing)相等的(de)管(guan)(guan)坯(pi)內(nei)(nei)注入液體(ti)(ti)，通(tong)過(guo)液壓(ya)(ya)(ya)(ya)(ya)機的(de)兩個水(shui)平側缸同步對中運(yun)動(dong)擠壓(ya)(ya)(ya)(ya)(ya)管(guan)(guan)坯(pi)，管(guan)(guan)坯(pi)受擠壓(ya)(ya)(ya)(ya)(ya)后體(ti)(ti)積(ji)(ji)變(bian)小，管(guan)(guan)坯(pi)內(nei)(nei)的(de)液體(ti)(ti)隨(sui)管(guan)(guan)坯(pi)體(ti)(ti)積(ji)(ji)變(bian)小而壓(ya)(ya)(ya)(ya)(ya)力(li)升(sheng)高，當達到等徑(jing)四(si)(si)通(tong)支管(guan)(guan)脹(zhang)出(chu)(chu)所(suo)需要(yao)(yao)的(de)壓(ya)(ya)(ya)(ya)(ya)力(li)時，金屬(shu)材(cai)料在側缸和(he)管(guan)(guan)坯(pi)內(nei)(nei)液體(ti)(ti)壓(ya)(ya)(ya)(ya)(ya)力(li)的(de)雙重作用(yong)(yong)下沿模具內(nei)(nei)腔流動(dong)而脹(zhang)出(chu)(chu)支管(guan)(guan)。等徑(jing)四(si)(si)通(tong)的(de)液壓(ya)(ya)(ya)(ya)(ya)脹(zhang)形(xing)工藝(yi)可(ke)一次成(cheng)形(xing)，生產效率(lv)較高；等徑(jing)四(si)(si)通(tong)的(de)主(zhu)管(guan)(guan)及肩部壁厚(hou)均有(you)增(zeng)加(jia)。因無縫等徑(jing)四(si)(si)通(tong)的(de)液壓(ya)(ya)(ya)(ya)(ya)脹(zhang)形(xing)工藝(yi)所(suo)需的(de)設備噸(dun)位(wei)較大，目前(qian)國內(nei)(nei)主(zhu)要(yao)(yao)用(yong)(yong)于(yu)小于(yu)DN400的(de)標(biao)準壁厚(hou)等徑(jing)四(si)(si)通(tong)的(de)制造。其適用(yong)(yong)的(de)成(cheng)形(xing)材(cai)料為冷作硬化傾向相對較低的(de)低碳鋼、低合金鋼、不(bu)銹鋼，包括一些(xie)有(you)色金屬(shu)材(cai)料，如銅、鋁、鈦等。

2、熱壓成形

等徑(jing)(jing)(jing)(jing)四(si)通(tong)(tong)(tong)(tong)熱壓(ya)成形(xing)是(shi)將(jiang)大于(yu)等徑(jing)(jing)(jing)(jing)四(si)通(tong)(tong)(tong)(tong)直(zhi)徑(jing)(jing)(jing)(jing)的(de)(de)(de)管(guan)(guan)(guan)坯(pi)(pi)，壓(ya)扁約(yue)至等徑(jing)(jing)(jing)(jing)四(si)通(tong)(tong)(tong)(tong)直(zhi)徑(jing)(jing)(jing)(jing)的(de)(de)(de)尺寸(cun)，在(zai)拉(la)伸支(zhi)管(guan)(guan)(guan)的(de)(de)(de)部位(wei)開一(yi)個(ge)孔。管(guan)(guan)(guan)坯(pi)(pi)經加熱，放入成形(xing)模中，并在(zai)管(guan)(guan)(guan)坯(pi)(pi)內裝入拉(la)伸支(zhi)管(guan)(guan)(guan)的(de)(de)(de)沖(chong)(chong)模；在(zai)壓(ya)力的(de)(de)(de)作用(yong)下管(guan)(guan)(guan)坯(pi)(pi)被(bei)徑(jing)(jing)(jing)(jing)向(xiang)(xiang)壓(ya)縮(suo)，在(zai)徑(jing)(jing)(jing)(jing)向(xiang)(xiang)壓(ya)縮(suo)的(de)(de)(de)過程中金(jin)屬(shu)向(xiang)(xiang)支(zhi)管(guan)(guan)(guan)方(fang)向(xiang)(xiang)流動(dong)并在(zai)沖(chong)(chong)模的(de)(de)(de)拉(la)伸下形(xing)成支(zhi)管(guan)(guan)(guan)。整個(ge)過程是(shi)通(tong)(tong)(tong)(tong)過管(guan)(guan)(guan)坯(pi)(pi)的(de)(de)(de)徑(jing)(jing)(jing)(jing)向(xiang)(xiang)壓(ya)縮(suo)和支(zhi)管(guan)(guan)(guan)部位(wei)的(de)(de)(de)拉(la)伸過程而成形(xing)。與液壓(ya)脹形(xing)等徑(jing)(jing)(jing)(jing)四(si)通(tong)(tong)(tong)(tong)不同的(de)(de)(de)是(shi)，熱壓(ya)等徑(jing)(jing)(jing)(jing)四(si)通(tong)(tong)(tong)(tong)支(zhi)管(guan)(guan)(guan)的(de)(de)(de)金(jin)屬(shu)是(shi)由管(guan)(guan)(guan)坯(pi)(pi)的(de)(de)(de)徑(jing)(jing)(jing)(jing)向(xiang)(xiang)運動(dong)進行補償(chang)(chang)的(de)(de)(de)，所以也稱(cheng)為徑(jing)(jing)(jing)(jing)向(xiang)(xiang)補償(chang)(chang)工藝。